Previously many types of portable air conditioners have been used to provide an effective means for cooling aircraft on the ground. These air conditioners historially include belt driven blowers and fans, direct driven compressors with flexible couplings direct driven motors for the condenser fans and blowers also semi-hermetic refrigerant compressors and a myriad of other combinations. Part of the novelty of the invention is the combination of the rotating drive components being directly connected to the engine without the use of speed changing or resilient drive mechanisms.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention however, the following U.S. patents were considered related:
______________________________________ U.S. PAT. NO. INVENTOR ISSUE DATE ______________________________________ 4,419,866 Howland Dec. 13, 1983 4,272,967 White et al Jun. 16, 1981 3,543,838 White Dec. 1, 1970 2,887,583 Talmey May 26, 1959 2,738,655 Gumpper Mar. 20, 1956 2,338,931 Gould et al Jan. 11, 1944 ______________________________________
Howland in U.S. Pat. No. 4,419,866 teaches a dual speed diesel engine driving a refrigerant compressor and a control system that starts and stops the engine upon temperature control demand. While the control system is not relevant the prior art driving the compressor directly by the engine is. Although not disclosed, the drive method and means for providing air flow through the con denser and evaporator sections in typical units produced by the assignee are well known in the art and include a flexible coupling or centrifugal clutch with belt driven fans and blowers.
White et al do indeed teach an air conditioning system for aircraft using a diesel engine as the prime mover. White et al approach in U.S. Pat. No. 4,272,967 is to attach an electrical generator to the diesel engine and operate the entire refrigeration system, including controls, with electrical alternating current thus generated. This prior art approach allows both conditioned air and condenser air to be moved by rotating blowers and fans coupled to electric motors. The refrigerant compressors are the semi-hermetic type with their own inherent suction gas cooled electric motors.
U.S. Pat. No. 3,543,838 issued to White discloses an air conditioning system with the refrigerant compressor provided by the truck engine radiator fan. The evaporator blower is rotated by an electric motor powered from the truck ignition system. It is apparent that this prior art while containing the relevant elements approaches the problem entirely different than the instant invention.
Talmey in U. S. Pat. No. 2,887,853 directs his intentions toward a refrigeration system for rail cars utilizing an operating shaft directly connected to the rotary element of the compressor. The fans are rotated by an electric motor, and controls selectively operate the engine at low and high speeds with a two function throttle control mechanism.
Gumpper et al are concerned with air conditioning a refrigerator car, truck or the like that consists of a unitary system mounted on a single base that is insertable and removable from a dedicated space in which it is to be used in the vehicle. A diesel engine is coupled with a conventional refrigerant compressor through a coupling device. The air movement for the condenser and radiator is provided by an individual single blower and the evaporator air is circulated by a pair of blowers all attached to single shaft driven by a set of belts from the front crankshaft of the engine.
For background purposes and as indicative of the art to which the invention relates reference may be made to the patent of Gould et al.